Envelope manufacture



Nov. 5, 1957 e. H. KENNEDY, JR 2,811,995

ENVELUPE MANUFACTURE 2 Sheets-Sheet 1 Filed Feb. 29, 1956 INVENTOR.George HKennedy Jr.

G. H. KENNEDY, JR 2,811,905

ENVELOPE MANUFACTURE Nov. 5, 1957 2 Sheets-Sheet 2 Filed Feb. 29. 1956INVENTOR. GEORGE H. KENNEDY Jr.

Z/M J. M

United States Patent 2,811,905 ENVELOPE MANUFACTURE Application February29, 1956, Serial No. 568,493 12 Claims. (Cl. 93-452) This invention,like the invention set forth in Vincent E. Heywood application SerialNo. 375,091, filed August 19, 1953 (now abandoned), for Manufacture ofEnvelopes and its continuation-impart, Serial No. 670,981, filed July10, 1957), relates to methods and mechanisms for obtaining extremelyhigh rates of production, in the rotary machine manufacture ofenvelopes.

In envelope manufacture by the sequences and arrangements of theaforesaid Heywood applications, extremely high rates of envelopeproduction can be achieved. Actually, the envelope production rate,under such sequences and arrangements, is limited only by the speed atwhich it is practicable and feasible to perform on the successiveenvelope blanks in process the two flap folding operations which areessential to their conversion into envelopes. These flap foldingoperations, for each blank, are an initial infolding of its side flaps,and a subsequent folding over of its back or bottom flap into adhesiveseam connection with its side fiaps.

That is to say, with the invention of the aforesaid copending Heywoodapplications, the rate of envelope production suffers no limitation orcurtailment whatsoever, from the operations of applying to thesuccessive blanks (l) the glue for sticking the envelope seams, and/ or(2) the seal flap glue or gumming. This is because of the fact that thegluing is applied, progressively and en masse, to seal flap margins aswell as to seal flap margins of the successive blanks, with the lattercollected, for each glue applying operation, in a slow speed closelyshingled or stepped assembly that exposes only the desiredglue-receiving flap margins to the action of the gluing roller or wiper.

One difliculty or drawback however, with these procedures of theaforesaid copending applications, is the need for the closely shingledblanks, once their leading back flap margins have received the seamsticking glue, to be completely de-shingled or individualized, and thento undergo a second shingling operation, in opposite relation to thefirst, before their trailing seal flap margins can be coated with glue.

The instant invention overcomes this difficulty or drawback, by asequence of operations which, in achieving an envelope production ratenearly as high as the aforesaid procedures, requires only a singleshingling operation to be performed on the blanks.

Other and further objects and advantages of this in vention will be madeapparent by the following detailed description thereof, taken inconnection with the accompanying drawings, in which Fig. l is a planview, illustrating schematically the envelope making method andapparatus of this invention, but omitting, for the sake of clearness,certain glue receptacles and glue transfer rolls.

Fig. 2 is a vertical sectional view on the center line 2-2 of Fig. l,and showing also the elements omitted from Fig. 1.

Fig. 3 is a large scale view of one of the envelopes Patented Nov. 5,1957 "ice by this invention, from blanks of the form end of Fig. 1.

produced shown at the right-hand Fig. 4 is a large scale fragmentarydiagrammatic view, as seen from the underside of Fig. 1, showing how theblanks in process undergo partial deshingling from a closely shingledrelation to a shallowly shingled relation.

This invention achieves extremely high rates of production, in themanufacture of triangular flap" or diagonal seam envelopes, from blanksof any conventional shape, such as shown in Fig. l by the blanks A, A.Each blank A, as shown, consists of the usual rectangular body portion1, having opposite triangular side flaps 2, 2, a deep triangular backflap 3 and a shallow seal or closure flap 4. It is contemplated that asuccession of these or other appropriately-shaped blanks will be fedfiatwise one by one at high speed, either from a supply stack (notshown) or, in the case of blanks of substantially diamond or rhombicshape, from suitable oblique cutoff devices operable on a travelingpaper web to sever successive blanks therefrom. In either case thesuccessive blanks. such as A, A, by the action of suitable feed rolls orthe like (not shown except at 5, 5 Figs. 1 and 2) are advanced rapidly,from right to left, in spaced apart relation, toward the illustratedmechanism, each with its back flap 3 leading and its seal flap 4trailing; preferably each flat blank A, during its initial high speedadvance, receives lines of scoring 20 at the base of each side flap, anda line of scoring 3a at the base of its back flap 3.

The initial operation here, the same as in the aforesaid copendingHeywood application. is to fold inwardly the side flaps 2, 2 of thesuccessive advancing spaced-apart blanks A, A. For this purpose, theillustrated mechanism, in the path of said rapidly advancing spacedblanks, provides conventional plowshare folding devices 6, 6 (shown onlyin Pig. 1) equipped with the usual high speed forwarding rolls 7, 7 andwith suitable traction rolls 7', 7-these sets of rolls 7, 7' cooperatingto continue each blanks advance at the same high speed as that impartedby the feed rolls 5, 5. The plowshare" folders 6, 6 operate in the usualand well-known manner to obtain, by each blanks movement therethrough,the progressive turning, inwardly and downwardly, on score lines 2a, 2a,of its side flaps 2, 2 against its body portion 1, to give the blank theopposite parallel side edge folds 8, 8 as shown by the blank marked B inFig. l.

The next operation on the successive partly-folded blanks B, B is toprogressively collect them, one after another, in a deep shingled slowspeed assembly, as shown at D, Fig. 1, for the progressive en massegumming of their trailing seal flap margins. To this end, the mechanismprovides, beyond the plowshare folders 6, 6, suitable high-speed rolls9, 9 operating at the same high peripheral speed as the preceding rolls5, 5 and 7, 7'. Said rolls 9, 9 are appropriately relieved, as shown at10, 10, Fig. 2, so as to release each blank B and to discontinue itshigh'speed advance, substantially at the instant that back flap areas12, 12 just ahead of its side edge folds 8, 8 encounter and are seizedby a suitable low speed blank forwarding means, here shown as consistingof a lower roll 11 and a cooperating pair of upper narrow rolls or discs11', 11' the latter engaging the successive blanks B only along zonesadjacent to their side edge folds 8, 8. These slow speed rolls 11, 11 asa unit are made adjustable toward and away (see arrows X, Fig. 2) fromthe high-speed rolls 9, 9, to accommodate the spacing to blanks orgreater or less dimension, measured in the direction of their travelthrough the mechanism.

Rolls 11, 11 have a peripheral speed which is only a very small fraction(here with blanks A, A about onesixteenth) of the peripheral speed ofthe preceding rolls 9, 9. Thus each partly-folded blank B as itencounters the rolls 11, 11' has its speed of advance so drasticallyalmost entirely overtaken "by the "next is slowed down by the rolls 11,11. In this overtaking or shingling action, provision is made for eachfast moving blank B to be projected beneath the trailing seal flap 4 ofthe preceding slowed down blank, by disposing the bite of the slow rolls11, 11' at a slightly higher level than the bite of fast rolls 9, 9, asshown in Fig. 2.

Thus by the conjoint action of fast rolls 9, 9 and slow rolls ll, 11',the successive partly-folded blanks B are progressively collected in aslow moving close or deeply shingled assembly D. Therein each blank Boverlies and covers me next following blank B except for an exposednarrow area, of shingle dimension S along the inside margin of thelatters trailing seal flap 4. Beyond the range of forward adjustment ofthe rolls 11, 11 are provided suitable means for rolling or spreadingglue, for envelope sealing purposes, upon the adjacent exposed trailingseal flap margins of the blanks B, Bof said shingled assembly D. Suchmeans, as shown, consists of a lower roller 13 and an upper shorter roll14, both operating at the same low peripheral speed as the shinglingrolls 11, 11, to continue the latters slow speed advance of the shingledassembly glue supply tub 16, as shown in Fig. 2. This glue, by the slowrotation of roll 14, is continuously and progressively spread onto theexposed trailing seal flap margins of the blanks B, B, of assembly D, ina wide band or stripe, as indicated by the strippling in Fig. l.

The above-described operation, except for the fact that the constituentblanks of slow moving assembly D have had their side flaps initiallyinfolded, corresponds to the so-called coating or spreading process ofseal flap gumming, well-known in the art, and described in Winkler &Dunnebier Patent No. 2,132,227 of October 4, I938 and many otherpatents.

This operation gives to every seal flap of the successive shingledblanks B, B a glue-coated margin 17 which is of uniform widththroughout, with squared-off ends. The iatters conventional inwardspacing from the blanks side edge folds 8, 8 gives to shingled assemblyD, beyond the edges of the seal gluing thereon, the opposite marginalunglued areas l8. 18, which enable the assemblys slow advance to becontinued. by the contact with said areas 18, 18 of a pair of spacedupper narrow for warding rolls or discs 20, 20, cooperating with a lowerfull length roll 21-said rolls 20, 21 having the same low peripheralspeed as the rolls 1], 11 and 13, 14.

These final slow speed rolls 2t], 21 maintain their control of eachblank B of assembly D during such blanks movement, at slow speed, acrossa suitable horizontal support element 22. The latter extends forwardly,as best shown in Fig. 2, from the vicinity of the final slow rolls 20,21 to the vicinity of the bite between a lower full length roll 23, anda cooperating centrally positioned narrow roll or disc 24 mounted on ashaft 25. The bite of rolls 23, 24 is forwardly spaced from the bite ofslow rolls 20, 21 by nearly the full blank length. That is to say, thisspacing is such that the slow assemblys foremost and topmost blank(marked C in Figs. 1 and 4) will have its trailing seal flap edgereleased by the bite of slow rolls 20, 21, at just the instant that itsleading back flap tip or apex 26 is seized by the bite of the rolls 23,24. These rolls 23, 24 as a unit are made adjustable toward and away(see arrows y Fig. 2) from the final slow speed rolls 20, 21, toaccommodate the last mentioned spacing to blanks of greater or lessdimension, measured in the direction of their travel through theillustrated mechanism.

The peripheral speed imparted to the rolls 23, 24 is only about one-halfthe peripheral speed imparted to But this gives to the rolls 23, 24 aperipheral speed which shared in common by the shingling rolls 11, 11',the glue applying rolls 13, 14 and the final assembly forwarding rolls20, 21. In consequence of this last, each successive foremost blank C ofslow moving assembly D, upon encountering (by its tip or apex 26) thebite 23, 24, has its forward motion sharply accelerated. Thisacceleration is such that each so-seized foremost blank C is propelledforwardly through a distance "d" Fig. 4 (or from position C to positionC in Fig. 1) in the time that it takes for the next-following blank ofassembly D, under the influence of slow rolls celerated by rolls 23, 24,preceding position C blank, and so on, indefinitely, for each succeedingforemost and topmost blank of assembly D.

It is particularly to be noted that the narrow intermedihas acircumference that is equal in length to the blank displacement distancea; and that said roll 24 is suitably relieved or recessed, as shownescape contact at each revolution with the wet glue coated area 17 oneach passing blanks seal flap margin. Also to be particularly noted isthe fact that the principal burden on these intermediate speed rolls 23,24 is merely to initiate the above-described acceleration of eachsuccessive foremost blank of assembly D; that is to say, once any suchblank, by action of rolls 23, 24 on its leading apex 26 has haditsfaster movement commenced, the blanks continued steady propulsion atthis faster rate is taken over and subsequently maintained by the ingrollers, all operating at the same intermediate peripheral speed as thatimparted to the rolls 23, 24.

One such set of intermediate speed rolls consists of a l, in closerrelation to the final slow rolls 20, 21 than the rolls 23, 24. Despitethis closer relation, a blank of assembly D, in its approach to blankposition C will not come under the influence of these intermediate speedrolls itsacceleration has been initiated by the. above The same is trueof the narrow rolls 25', 25' carried by the shaft 25 of central roll 24.Another set of intermediate speed rolls, consisting of a full length andcooperating upper narrow rolls or discs 31, 31 is arranged beyond theing of a full length lower roll 32, narrow rolls or discs 33, 33, isarranged as shown in Fig. 1, beyond the mechanisms seam gum imprintingstation G, presently to be described.

As clearly appears from Fig. l, the effect of accelerating formed into ashallowly shingled blank assembly E, which, exactly like that of VincentE. Heywood Patent No. 2,772,611, dated December 4, 1956, exposes inclose proximity to each other the two ditferent glue-receiving areas(leading side flap margins and trailing seal flap margin) of successiveadjacent blanks. Said blank assembly E herein, the same as the shallowlyshingled blank assembly E of said Heywood Patent No. 2,772,611, movespast the rotary glue imprinting device or devices of station G at aspeed which is approximately only about one-half the highest blank speedthrough the machine, at which the flap folding operations on thesuccessive spaced apart blanks are performed. Accordingly, at station G,any suitable rotary seam glue imprinting device 36, rotating (with itsplaten roll 36') in step with the intermediate speed of advance of theblank assembly E, will not attain a rotational speed at whichcentrifugal throw-01f of glue takes place until said highest blank speed(which determines the envelope production rate of the machine) is two orthree times greater than the highest permissible blank speed inconventional rotary envelope making machines of the prior art.Furthermore, the blank assembly E herein has the same ability as theblank assembly E of said Heywood Patent No. 2,772,611, to prevent suchglue as is thrown off centrifugally by rotary imprinting device 36, fromaccumulating on nearby machine surfaces, because it (said assembly E)covers all such surfaces.

The seam glue imprinting device 36 as herein shown is of multipleconstruction, and provides, at opposite ends of its shaft 37, two setsof matching narrow segments 38, 38' which are 180 degrees apart, andspaced from each other, circumferentially, by the distance d (Fig. 4)which, in shallowly shingled assembly E, separates the seam gluereceiving margins along leading side flap edges 34, 34 of adjacentoverlapped blanks. This multiple construction of the glue imprintingdevice 36 still further reduces its tendency for centrifugal gluethrow-off, by increasing its radius, since centrifugal force isinversely proportional to the radius of rotation. The segments 38, 38receive glue from a transfer roller 39 (Fig. 2) associated with aconventional glue receptacle 40. The rotary imprinting device 36 is sotimed with the advance of assembly E that said segments 38, 38 providesuccessive narrow seam glue imprints 41, 41 for each blanks infoldedside flaps 2, 2, just inwardly of the latters leading edges 34, 34.

While each successive foremost blank of assembly E is receiving its seamglue imprints 41, 41, as above described, its forward portions arepassing across a suitable support 42, beyond rolls 32, 33, at theintermediate assembly speed imparted by said rolls. Upon the release bysaid rolls 32, 33 of each such blank, the latter is speeded up,substantially as described in said Heywood Patent No. 2,772,611, inorder to draw it away from assembly E, for the folding over on scoreline 3a of its back or bottom flap 3, into seam-forming engagement withthe glue imprints 41, 41 of its infolded side flaps. Any suitablemechanism for thus progressively de-shingling the successive blanks, byrestoring to each in turn the high speed of advance imparted by therolls 5, 5, 7, 7 and 9, 9 may be employed.

As herein shown for this purpose, the mechanism provides, just beyondsupport 42, a hollow roller 43, journaled on a stationary hollow shaft44, and having counterclockwise rotation at the same peripheral speed asthe high speed rolls 5, 5, 7, 7 and 9, 9. The roller 43, for seizure ofeach blank along its score line 3a, just as said blank is released byintermediate speed rolls 32, 33, has a suction port or slot 45 (Fig. 2)whose inner end is in periodic communication with the interior of shaft44, through a port or opening 46 of limited angular extent; said shaftinterior is connected to any suitable source of suction, such as avacuum pump, not shown.

Figs. 1 and 2 show a foremost blank which has thus been suctionallygripped at its score line 3a by slot 45 of roller 43, and drawndownwardly by said rollers high speed rotation, away from assembly E,toward the line of bite between said roller 43 and an adjacent pressingand forwarding cylinder 47, which rotates clockwise at the same highperipheral speed as the roller 43.

Cylinder 47 is mounted, for its high speed rotation, on a stationaryhollow shaft 48 (Fig. 2) having its interior connected to said source ofsuction, and providing a longitudinal port 49 of substantially 90degrees angular extent, with which is adapted to periodically registerthe inner end of a slot or port 50 of the rotating cylinder 47. Saidslot 50 at its outer end serves for the suction seizure, on eachrevolution of said cylinder 47, of each individualized or de-shingledblank which, as above described, is drawn downwardly by the high speedcylinder 43.

The respective port 46 and 49 of hollow shafts 44 and 48 are sopositioned, as shown in Fig. 2, that suction through slot 50 becomesavailable, for blank seizure by cylinder 47, substantially coincidentalwith the cut-off of suction through slot 45, to release such blank fromthe roller or cylinder 43. The transfer of each blank from cylinder 43to cylinder 47 occurs as their respective ports or slots and come intoopposing substantial alinement, with the slot 50 seizing the blank inthe same location as the slot 45, viz., at or just behind its score line3a.

As each blank, upon seizure at its score line 3a by slot 45 movesdownwardly with cylinder 43, its forwardly projecting back fiap 3,beyond said score line undergoes an upward bending or deflection whichincreases to a pronounced transverse fold 51 (Fig. 3) as the downwardhigh speed blank movement, first by cylinder 43 and then by cylinder 47carries each de-shingled blank, score line 30 leading, between said twocylinders. The pressing action of said cylinders accentuates said fold,and is of course also exerted to press together the overlapped seamconnection of back flap 3 with the wet gluing 41, 41 of the infoldedside flaps 2, 2. The cylinder 47, as shown at 52, Fig. 2, is suitablyrelieved, to prevent its contact with the wet seal gum 17 on each blank,as the latters trailing seal flap 4 is drawn between the cylinders 43and 47. The cylinder 47 then delivers each envelope, as thus completed,to suitable feed belts 53, 54 running to drying mechanism, not shown,wherein the seal flap gum 17 is subject to prolonged drying.

I claim:

1. In the manufacture of envelopes from a succession of blanks advancingfiatwise at high speed in spaced relation with seal flaps trailing, theimprovement which consists in folding inwardly the side flaps of thesuccessive so-advancing spaced blanks, so progressively collecting thesuccessive partly-folded blanks in a low speed closely shingled assemblythat each blank thereof, except for the margin of its trailing seal flapis overlain by the preceding blank of said assembly, progressivelyspreading glue, in the low speed advance of said assembly, onto theso-exposed adjacent trailing seal flap margins of it successivepartly-folded blanks, progressively so increasing in succession thespeed of each foremost so-glued blank of said assembly as to justuncover, by its trailing seal flap edge, the leading margins of the nextblanks infolded side flaps, thereby to create a shallowly shingled blankassembly whose speed of advance is appreciably lower than the blankspeed at which the side flaps of the successive spaced blanks are foldedinwardly, and imprinting with glue at said appreciably lower speed thesuccessive exposed leading side flap margins of the blanks of saidshallowly shingled assembly.

2. In the manufacture of envelopes from a succession of blanks advancingfiatwise at high speed in spaced relation with seal flaps trailing, theimprovement which consists in folding inwardly the side flaps of thesuccessive so advancing spaced blanks, progressively collecting thesuccessive partly-folded blanks in a slow speed closely shingledassembly, for the progressive en masse gluing of their trailing sealflap margins, progressively partially deshingling said closely shingledblank assembly by speed up of each foremost so-glued blank thereof, butonly to an extent such that its trailing seal flap edge uncovers andexposes the leading edges of the next blanks infolded side flaps,thereby to create a shallowly shingled blank assembly whose speed ofadvance is between the high blank speed at which the blanks side flapsare folded inwardly and the low speed of said closely shingled blankassembly, and imprinting with glue, speed, the successive exposedleading side flap margins of the blanks of said shallowly shingledassembly.

3. In the manufacture of envelopes from a succession of blanks advancingflatwise at high speed in spaced relation with seal flaps trailing, theimprovement which consists in folding inwardly the side flaps of thesuccessive so advancing spaced blanks, progressively collecting thesuccessive partly-folded blanks in a slow speed closely shingledassembly, for the progressive en masse gluing of their trailing sealflap margins, progressively partially deshingling said closely shingledblank assembly by speed up of each foremost so-glued blank thereof, butonly to an extent such that its trailing seal flap edge uncovers andexposes the leading edges of the next blanks infolded at saidintermediate side flaps, thereby to create a shallowly shingled blank,

assembly whose speed of advance is between the high blank speed at whichthe blanks side flaps are folded inwardly and the low speed of saidclosely shingled blank assembly, imprinting with glue, at saidintermediate speed, the successive leading side flap margins of theblanks of said shallowly shingled assembly, progressively completing thedeshingling of the blanks of said intermediate speed assembly, byrestoring to each foremost fully glued blank thereof the initial highspeed at which the blanks side flaps are folded inwardly, and thenfolding over'the leading back flap of each successive deshingled blank,into adhesive seam connection with its side flaps.

4. In envelope making mechanism of the class described, means forrapidly advancing successive blanks llatwise in spaced relation, withtheir seal flaps trailing, means operative on each so-advancing blank tofold inwardly its side flaps, means for so progressively collecting thesuccessive partly-folded blanks in a low speed closely shingled assemblythat each blank thereof, except for the margin of its trailing sealflap, is overlain by the preceding blank of said assembly, means forprogressively spreading glue, in the low speed advance of said assembly,onto the so-exposed adjacent trailing seal flap margins of itssuccessive partly-folded blanks, means for progressively so increasingin succession the speed of each foremost so-glued blank of said assemblyas to just uncover, by its trailing seal fiap edge, the leading marginsof the next blanks infolded side flaps, thereby to create a shallowlyshingled blank assembly whose speed of advance is appreciably lower thantheblank speed at which the side flaps of the successive spaced blanksare folded inwardly, and means rotating in step with said appreciablylower speed for imprinting with glue the successive so-uncovcred leadingside flap margins of the blanks of said shallowly shingled assembly 5.In envelope making mechanism of the class described, means for rapidlyadvancing successive blanks fiatwise in spaced relation, with their sealflaps trailing, means operative on each so-advancing blank to foldinwardly its side 'flaps, means for progressively collecting thesuccessive partly-folded blanks in a slowspeed closely shingledassembly, for the progressive en masse gluing of their trailing sealflap margins, means for progressively partially deshingling said closelyshingled blank assembly, by speed up of each foremost -so-glued blankthereof, but only to an extent such that its trailing seal flap-edgeuncovers and exposes the leading edges of the next blanks infolded sideflaps, whereby to create a shallowlyshingled blank assembly whose speedof advance is between the high blank speed at which the blanks sidefiapsarc folded inwardly and the low speed of said closely shingledblank assembly, and means rotating in step with the intermediate speedof said shallowly shingled assembly. t'or imprinting with glue themarginal areas along the so-exposed leading side flap edges of eachblank or said shallowly shingled assembly.

6. ln envelope "making mechanism of the class described. means forrapidly advancing successive blanks Ilatwisc in spaced relation, withtheir seal flaps trailing,

means operative on each so-advancing blank to fold inwardly its sideflaps, means for progressively collecting the successive partly-foldedblanks in a slow speed closely shingled assembly, for the progressive enmasse gluing of their trailing seal flap margins, means forprogressively partially deshingling said closely shingled blankassembly, by speed up of each foremost so-glued blank thereof, but onlyto an extent such that its trailing seal flap edge uncovers and exposesthe leading edges of the next blanks infolded side flaps, whereby tocreate a shallowly shingled blank assembly whose speed of advance isappreciably lower than the blank speed at which the side flaps of therespective blanks are folded inwardly, means rotating in step with thespeed of advance of said shallowly shingled assembly for imprinting withglue the successive leading side flap margins of the blanks of saidshallowly shingled assembly, means for progressively deshingling saidshallowly shingled blank assembly, by restoring to each foremost fullyglued blank thereof the initial high speed at which its side flaps arefolded inwardly, and means for folding over the leading back flap ofeach successive deshingled blank, into adhesive seam connection with itsside flaps.

7. In the manufacture of envelopes from a succession of blanks advancingflatwise at high speed in spaced relation with seal flaps trailing, theimprovement which consists in folding inwardly the side flaps of thesuccessive so advancing spaced blanks, progressively collecting thesuccessive partly-folded blanks in a slow speed closely shingledassembly, for the progressive en masse gluing of their trailing sealflap margins, progressively partially deshingling said closely shingledblank assembly by speed up of each foremost so-glued blank thereof, butonly to an extent such that its trailing seal flap edge uncovers andexposes the seam glue receiving margins of the next blanks infolded sideflaps, thereby to create a shallowly shingled blank assembly whose speedof advance, is appreciably lower than the blank speed at which the sideflaps of the respective blanks are folded inwardly and imprinting withglue, at said appreciably lower speed, the so-exposed side flap marginsof the successive blanks of said shallowly shingled assembly.

8. In the manufacture of envelopes from a succession of blanks advancingflatwise at high speed in spaced relation with seal flaps trailing, theimprovement which consists in folding inwardly the side flaps of thesuccessive so advancing spaced blanks, progressively collecting thesuccessive partly-folded blanks in a slow speed closely shingledassembly, for the progressive en masse gluing of their trailing sealflap margins, progressively partially deshingling said closely shingledblank assembly by speed up of each foremost so-glued blank thereof, butonly to an extent such that its trailing seal flap edge uncovers andexposes the seam glue receiving margins of the next blanks infolded sideflaps, thereby to create a shallowly shingled blank assembly whose speedof advance is ,between the high blank speed at which the blanks sideflaps are folded inwardly and the low speed of said closely shingledblank assembly, and imprinting with glue, at said intermediate speed,the successive exposed seam glue receiving side flap margins of theblanks of said shallowly shingled assembly.

9. In the manufacture of envelopes from a succession of blanks advancingflatwise at high speed in spaced relation with seal flaps trailing, theimprovement which consists in folding inwardly the side flaps of thesuccessive so advancing spaced blanks, progressively collecting thesuccessive partly-folded blanks in a slow speed closely shingledassembly, for the progressive en masse gluing of their trailing sealflap margins, progressively partially deshingling said closely shingledblank assembly by speed up of each foremost so-glued blank thereof, butonly to an extent such that its trailing seal flap edge uncovers andexposes the scam glue receiving margins of the next blanks infolded sideflaps, thereby to create a shallowly shingled blank assembly whose speedof advance is between the high blank speed at which the blanks sideflaps are folded inwardly and the low speed of said closely shingledblank assembly, imprinting with glue, at said intermediate speed, thesuccessive seam glue receiving side flap margins of the blanks of saidshallowly shingled assembly, progressively completing the deshingling ofthe blanks of said intermediate speed assembly, by restoring to eachforemost fully glued blank thereof the initial high speed at which theblanks side flaps are folded inwardly, and then folding over the leadingback flap of each successive deshingled blank, into adhesive seamconnection with its side flaps.

10. In envelope making mechanism of the class described, means forrapidly advancing successive blanks flatwise in spaced relation withtheir seal flaps trailing, means operative on each so-advancing blank tofold inwardly its side flaps, means for progressively collecting thesuccessive part1 -folded blanks in a slow speed closely shingledassembly, for the progressive en masse gluing of their trailing sealflap margins, means for progressively partially deshingling said closelyshingled blank assembly, by speed up of each foremost so-glued blankthereof, but only to an extent such that its trailing seal flap edgeuncovers and exposes the seam glue receiving margins of the next blanksinfolded side flaps, whereby to create a shallowly shingled blankassembly whose speed of advance is between the high blank speed at whichthe blanks side flaps are folded inwardly and the low speed of saidclosely shingled blank assembly, and means rotating in step with theintermediate speed of said shallowly shingled assembly, for imprintingwith glue the successive so exposed side flap margins of each blank ofsaid shallowly shingled assembly.

11. In envelope making mechanism of the class de- 3 scribed, means forrapidly advancing successive blanks flatwise in spaced relation withtheir seal flaps trailing, means operative on each so-advancing blank tofold in wardly its side flaps, means for progressively collecting thesuccessive partly-folded blanks in a slow speed closely shingledassembly, for the progressive en masse gluing of their trailing sealflap margins, means for progressively partially deshingling said closelyshingled blank assembly, by speed up of each foremost so-glued blankthereof, but only to an extent such that its trailing seal flap edgeuncovers and exposes the seam glue receiving margins of the next blanksunfolded side flaps, whereby to create a shallowly shingled blankassembly whose speed of advance is appreciably lower than the blankspeed at which the side flaps of the respective blanks are foldedinwardly, means rotating in step with the speed of advance of saidshallowly shingled assembly for imprinting with glue the successive soexposed side flap margins of the blanks of said shallowly shingledassembly, means for progressively deshingling said shallowly shingledblank assembly, by restoring to each foremost fully glued blank thereofthe initial high speed at which its side flaps are folded inwardly, andmeans for folding over the leading back flap of each successivedeshingled blank, into adhesive scam connection with its side flaps.

12. Envelope making mechanism as claimed in claim 10, in which therotary glue imprinting means provides a plurality of scam glueimprinting segments.

References Cited in the file of this patent UNITED STATES PATENTS June2, 1931 Ian. 16, 1934

